JPS601627A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent jitter and to obtain a tape having a long life by coating a lubricant on a ferromagnetic metallic thin film formed on a support while keeping the electric potential of the thin film constant so as to prevent the thickness of a lubricant layer from being made ununiform owing to a change in electric charge on the surface of the thin film. CONSTITUTION:A ferromagnetic metallic thin film 2 is formed on a support 1 such as a polyethylene terephthalate film by vacuum deposition or other method, and a soln. 6 of a lubricant such as stearic acid is coated on the film 2. The thickness of the soln. 6 is regulated by rotating a metaling roll 7 in the direction of an arrow C while rotating an applicator roll 5 in the direction of an arrow B, and the resulting material having a formed lubricant soln. layer 8 is sent to a drying stage A. In order to keep the surface electric potential of the magnetic layer 2 constant before coating the lubricant, the base tape 4 is sent after holding between a backup roller 13 and a potential regulating roller 11 with high electric conductivity grounded through a brush 12. The adhesion of a lubricant layer 3 is prevented from being made ununiform owing to ununiformity in electrostatic charge during stripping when the base tape 4 is rewound, and a magnetic recording medium having superior durability is obtd.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、耐久性の優れた金属薄膜型の磁気記録媒体の
製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a metal thin film type magnetic recording medium with excellent durability.

従来例の構成とその問題点 近年、磁気記録の高密度化の要望の高寸りと共に、強磁
性金属薄膜を磁気記録層とする磁気記録媒体の開発が各
方面で進められている。2. Description of the Related Art Structures of Conventional Examples and Their Problems In recent years, with the increasing demand for higher density magnetic recording, development of magnetic recording media having a magnetic recording layer made of a ferromagnetic metal thin film has been progressing in various fields.

磁気記録媒体の基本構成は第１図に断面図で示されるよ
うに、支持体１上に真空蒸着法、スパッタリング法等の
薄膜形成手段によ多形成された強磁性金属薄膜２と、強
磁性金属薄膜２の耐摩耗性向上等の目的で配される潤滑
剤塗布層３とから成り、必要に応じて、図示していない
が、非磁性薄膜、軟磁性薄膜、支持体１０強磁性金属薄
膜２を有する面と反対側の面に配される塗布層等が構成
要素として付加されるものであるＯ しかし、かかる磁気記録媒体は、用いられる強磁性金属
薄膜２の厚みが、０．３μｍ以下と薄いため支持体１の
表面粗さが、そのｉｔ強磁性金属薄膜２の表面粗さにな
るため極めて平滑な支持体１を用いなくてはならない。The basic structure of the magnetic recording medium, as shown in the cross-sectional view in FIG. It consists of a lubricant coating layer 3 disposed for the purpose of improving the wear resistance of the metal thin film 2, and as necessary, a non-magnetic thin film, a soft magnetic thin film, a ferromagnetic metal thin film on the support 10, although not shown in the drawings. However, in such a magnetic recording medium, the thickness of the ferromagnetic metal thin film 2 used is 0.3 μm or less. Because the support 1 is so thin, the surface roughness of the support 1 becomes the surface roughness of the ferromagnetic metal thin film 2, so an extremely smooth support 1 must be used.

従って、第１図の構成の磁気記録媒体は、回転シリンダ
、回転ヘッド等を構成要素とするヘリカル走査型のビデ
オチープレコーグ１１．下Ｖ、Ｔａａという）に於て利
用する時、大きな摩擦を受けるために潤滑剤を選んでも
、Ｖ、Ｔ、Ｒでのくり返し使用により走行が不安定にな
り再生信号が時間方向でゆらぐ、いわゆるジノターガ発
生し、再生画面がゆれたり曲ったりする不都合があった
。Therefore, the magnetic recording medium having the configuration shown in FIG. 1 is a helical scanning type video recorder 11. Even if a lubricant is selected to receive large friction when used in V, T, and R (lower V, Taa), repeated use at V, T, and R will cause the running to become unstable and the reproduction signal to fluctuate in the time direction. There was an inconvenience that the playback screen would shake or bend due to the generation of ginotarga.

特に前記現象は、磁気記録媒体の長手位置により強く現
れる個所と目視観察ではジッターを無視できる部分のあ
ることを追求した結果、塗布機を用いて潤滑剤を塗布す
る時、強磁性金属薄膜の表面が電位を有し且つその電位
が長手位置で変化する現象と強い相関があることを見出
した。In particular, as a result of pursuing the fact that there are parts where the above phenomenon appears more strongly in the longitudinal position of the magnetic recording medium and parts where jitter can be ignored by visual observation, we found that when applying lubricant using a coating machine, the surface of the ferromagnetic metal thin film It has been found that there is a strong correlation with the phenomenon that has a potential and that the potential changes with the longitudinal position.

発明の目的 本発明は耐久性の優れた金属薄膜型の磁気記録媒体の製
造方法を提供することを目的とする。OBJECTS OF THE INVENTION An object of the present invention is to provide a method for manufacturing a metal thin film type magnetic recording medium with excellent durability.

発明の構成 本発明は支持体上に形成した強磁性金属薄膜上に潤滑剤
溶液を塗布する際に、前記強磁性金属薄膜を一定の電位
に保持することを特徴とする。Structure of the Invention The present invention is characterized in that when a lubricant solution is applied to a ferromagnetic metal thin film formed on a support, the ferromagnetic metal thin film is held at a constant potential.

強磁性金属薄膜を構成する結晶粒子は、１０八から２０
０人ぐらいの範囲の酸化層を通常有しているため潤滑剤
を塗布する時、巻回された状態から巻き戻される際大気
中で剥離帯電し、表面に電荷が残りその電荷量は一定し
ていない。The number of crystal grains constituting the ferromagnetic metal thin film is 108 to 20.
Since it normally has an oxidized layer in the range of about 0.0%, when applying lubricant, when it is unwound from the wound state, it is detached and charged in the atmosphere, and a charge remains on the surface and the amount of charge is constant. Not yet.

又磁気記録媒体は大量に生産されるものであるから連続
して処理、加工される単位は５．ｏｏｏ　ｙｄ程の大き
な面積になるため、潤滑剤溶液も循環圧送される。Also, since magnetic recording media are produced in large quantities, the number of units that are continuously processed and processed is 5. Since the area is as large as ooo yd, the lubricant solution is also circulated and pumped.

その際潤滑剤溶液も配管、ポンプ、容器壁、コーク−ヘ
ッド等の構成機材と摩擦帯電する。At this time, the lubricant solution also becomes charged by friction with the components such as piping, pumps, container walls, and coke heads.

塗布する相手側と塗布する潤滑剤溶液が両方共同じ極性
、同じ電位に帯電することは考えにくいことであり、こ
のため強磁性金属薄膜と潤滑剤溶液との間で塗布される
短時間の間に反撥現象が生じたり、放電現象が発生して
潤滑剤層の形成が不均一になる。It is difficult to imagine that both the other side to be coated and the lubricant solution to be coated will be charged to the same polarity and the same potential, and for this reason, during the short period of time during which the ferromagnetic metal thin film and the lubricant solution are coated. A repulsion phenomenon occurs or a discharge phenomenon occurs, resulting in uneven formation of the lubricant layer.

本発明はかかる問題解決のために、塗布機の構成を吟味
して確実に潤滑剤溶液を塗布する際の強磁性金属薄膜を
接地することで均一な潤滑剤層を得ることに成功したこ
とに基ずくものである。In order to solve this problem, the present invention has succeeded in obtaining a uniform lubricant layer by carefully examining the configuration of the coating machine and grounding the ferromagnetic metal thin film when applying the lubricant solution. It is based on

更に検討を加えた結果、接地によらなくても、一定の電
位に保持することで同様の効果が確認できた。As a result of further investigation, it was confirmed that the same effect could be obtained by holding the potential at a constant level without relying on grounding.

実施例の説明 第２図は本発明の実施に用いた塗布機の要部構成図であ
る。DESCRIPTION OF THE EMBODIMENTS FIG. 2 is a block diagram of the main parts of a coating machine used in carrying out the present invention.

支持体１と強磁性金属薄膜２とから成る磁気記録媒体用
原波４（以下これを基板という）は矢印入方向に移動す
る。An original wave 4 for a magnetic recording medium (hereinafter referred to as a substrate) consisting of a support 1 and a ferromagnetic metal thin film 2 moves in the direction indicated by the arrow.

基板４の強磁性金属薄膜２を有する側の表面にアプリケ
−クロール５により運ばれる潤滑剤溶液６が塗布され、
潤滑層８が形成される。A lubricant solution 6 carried by an applicator roll 5 is applied to the surface of the substrate 4 on the side having the ferromagnetic metal thin film 2;
A lubricating layer 8 is formed.

この際均−な潤滑層８の厚みを得るために計量が行われ
、この場合は矢印Ｂ方向に回転するアプリケ−クロール
５と反対のＣ方向に回転するメタリングロール７とのす
き間で主として調節されるものである。At this time, measurement is performed to obtain an even thickness of the lubricating layer 8, and in this case, adjustment is mainly made by the gap between the applicator roll 5 rotating in the direction of arrow B and the metering roll 7 rotating in the opposite direction C. It is something that will be done.

一定のウェット厚みを有する潤滑層８を付与された基板
４は図示しない乾燥炉に進み、その後巻き取らｊ、る。The substrate 4 provided with the lubricating layer 8 having a certain wet thickness is advanced to a drying oven (not shown) and then wound up.

アプリケータロール６により過剰に運ばれた潤滑剤性液
６の一部はメタリングロール７に転写し、ドクターブレ
ード９によりかき落されて潤滑剤溶液６の容器１０に戻
る。A portion of the lubricant liquid 6 carried in excess by the applicator roll 6 is transferred to the metering roll 7, scraped off by the doctor blade 9, and returned to the container 10 of the lubricant solution 6.

１１は少なくとも表面が良導電性材料よりなる電位規制
ローラーであり、この電位規制ローラー１１はブラフ１
２により接地されている。Reference numeral 11 denotes a potential regulating roller whose surface is made of a highly conductive material.
It is grounded by 2.

１３はバックアップローラであり、バックアップローラ
１３は基板４を電位規制ローラー１１とではさんで強磁
性金層薄膜２の電位を一定に保持させる。バックアップ
ロール１３は、ゴムで構成するのが好ましい。Reference numeral 13 denotes a backup roller, and the backup roller 13 holds the substrate 4 between the potential regulating roller 11 and the potential of the ferromagnetic gold layer thin film 2 at a constant level. The backup roll 13 is preferably made of rubber.

１４はフリーローラーであり潤滑層８を形成する潤滑剤
溶液６が乾燥するまでは基板４の潤滑層８側と反対側の
面に接するものである。Reference numeral 14 denotes a free roller which contacts the surface of the substrate 4 on the side opposite to the lubricant layer 8 side until the lubricant solution 6 forming the lubricant layer 8 dries.

電位規制ローラ１１は、潤滑剤溶液６が塗布される位置
に近くなるように構成するのが奸才しい。It is wise to configure the potential regulating roller 11 so that it is close to the position where the lubricant solution 6 is applied.

また、電位規制ローラー１１の電位は接地によらず直流
電のにより一３００Ｖ〜＋３００Ｖの範囲で調整するこ
とができる。この範囲を越えると強磁性金属薄膜２にピ
ンホールが発生することがあるので好捷しくない。Further, the potential of the potential regulating roller 11 can be adjusted in the range of -300V to +300V by direct current, not by grounding. Exceeding this range is not desirable because pinholes may occur in the ferromagnetic metal thin film 2.

尚、本発明は、上記実施例に示す塗布機以外の他の実布
機においても同様に実施可能であり、捷た潤滑剤溶液の
種類、支持体の種類１強磁性金属薄膜の種類について下
記の具体的な実施例についても全く同じ作用効果を有す
るものである。It should be noted that the present invention can be carried out in the same manner using other coating machines other than the coating machines shown in the above embodiments, and the types of the slender lubricant solution, the type of support 1 and the type of ferromagnetic metal thin film are as follows. The specific embodiments have exactly the same effects.

本発明の実施と比較例の実施に用いた塗布機の寸法構成
等は次の通りである。The dimensions and configuration of the coating machine used in the implementation of the present invention and the comparative examples are as follows.

アプリケータロール６の径は２０口、アプリケ−クロー
ル５と基板４が接する位置と径６Ｃｒｎの電位規制ロー
ラ１１との距離１ｄ　１０　ａｎで、比較例は電位規制
ロール１１をはずし、その位置に静電電圧計を近ずけて
基板４の表面電位を計測した。The diameter of the applicator roll 6 is 20 holes, and the distance between the position where the applicator roll 5 and the substrate 4 contact and the potential regulating roller 11 with a diameter of 6Cr is 1 d 10 an. The surface potential of the substrate 4 was measured by bringing a voltage meter close.

以下さらに具体的な実施例を示す。More specific examples will be shown below.

（実施例　１） 厚さ９μｍのポリエチレンテレフタレートフィルム（以
下フィルム八と称す）を８０’Ｃの媒体を周囲に循環さ
せが筒状キャン（図示せず）の外周に沿ってフィルムＡ
を２２　ｎＬ／　ｍｍで移動させながら二元蒸発源を用
いて加熱電子ビームをそれぞれｃｏ　に対して７０　Ｋ
Ｗ　、、Ｃｒに対して３６　ＫＶｉｌ投入するように制
御してＣｒが１９重量％になる強磁性金属薄膜０．１９
μｍの厚さで形成した基板を得た。(Example 1) A polyethylene terephthalate film (hereinafter referred to as Film 8) having a thickness of 9 μm was circulated around a 80'C medium, and a film A was formed along the outer periphery of a cylindrical can (not shown).
Heating the electron beam using a binary evaporation source while moving at 22 nL/mm at 70 K for each co
0.19 ferromagnetic metal thin film with 19 wt% Cr by controlling the input of 36 KVil for W, Cr
A substrate formed with a thickness of μm was obtained.

前記蒸着時の真空度は８　Ｘ　１０　ＴＯＲＲであり、
得られ、た強磁性金属薄膜は垂直磁化膜である。The degree of vacuum during the vapor deposition is 8×10 TORR,
The obtained ferromagnetic metal thin film is a perpendicularly magnetized film.

前記基板を大気中に取出し４時間後に潤滑剤溶液を乾燥
後の膜厚が夫々約５ｏ人になるように前述の塗布機を用
いて基板に塗布した。The substrates were taken out into the atmosphere, and 4 hours later, a lubricant solution was applied to the substrates using the above-mentioned coating machine so that the film thickness after drying was approximately 50 mm.

用いた潤滑剤溶液はｎ−へキサン中にミリスチン酸を溶
解させたもので塗布速度（ｒ：ｉ　６０　ｍ／ｍｊｎで
ある。The lubricant solution used was one in which myristic acid was dissolved in n-hexane, and the coating speed was (r: i 60 m/mjn).

５、○００　７７１長の基板を５等分して潤滑剤溶液の
塗布を１．○○○ｍ単位で行って、８鵡幅の磁気テープ
にしてＶ、Ｔ、Ｒてのくり返し走行を行った。5, 00 771 Divide the board into 5 equal parts and apply the lubricant solution in 1. The magnetic tape was run in units of ○○○m, and the tape was repeatedly run in V, T, and R directions.

比較例として電位規制ロール１１をはずし、その位置で
基板の表面電位を観測した。As a comparative example, the potential regulating roll 11 was removed and the surface potential of the substrate was observed at that position.

その１例を第３図に示した。このように比較例では表面
電位が不安定であったが実施例では接地電位で、この両
者の差はくり返し走行時のテープ長手位置での場所によ
る摩擦係数の増加現象として現われ、その結果再生画面
がゆらぐジッターとして現れたもので、長手に１００ｍ
を１巻として本発明品６０巻、比較例６０巻を２５°ｃ
、６ｏ％Ｒ，Ｈ’、３０″Ｃ’＋　８５．％　Ｒ、Ｈ−
’　、　（７Ｊ）環境テ調ヘタトコろ、それぞれ１００
回のくり返し使用で本発明品はジッターがはっきり画面
で判別できるものが皆無であったのに対して比較例では
２５°Ｃ２６０％Ｒ、Ｈ、テ３０　％、３０°Ｃ、８５
％　Ｒ、Ｈｏｆ　６０　％　（Ｄテープがジッター成分
としてはっきり認められた。An example is shown in Figure 3. In this way, the surface potential was unstable in the comparative example, but it was the ground potential in the example, and the difference between the two appears as an increase in the coefficient of friction depending on the longitudinal position of the tape during repeated running, and as a result, the playback screen It appeared as a fluctuating jitter, and the length was 100 meters.
60 volumes of the invention product and 60 volumes of the comparative example at 25°C.
, 6o%R,H', 30''C'+ 85.%R,H-
' , (7J) Environmentally friendly, 100 each
After repeated use, the products of the present invention had no jitter that could be clearly seen on the screen, whereas the comparative example had 25°C, 260% R, H, Te 30%, 30°C, 85°C.
% R, Hof 60% (D tape was clearly recognized as a jitter component.

ジッター発生個所と表面電位の関係を追求したところ第
３図に示すように電位が急変している所、すなわち、矢
印り、Ｅ、Ｆのところに対応していることが明らかとな
った。When we investigated the relationship between the locations where jitter occurred and the surface potential, it became clear that the locations corresponded to the locations where the potential suddenly changed, ie, the locations indicated by arrows E and F, as shown in FIG.

（実施例２） 厚さ７μｍの芳香族ポリアミドフィルム（以下フィルム
Ｂと称す）を２００°Ｃの媒体を周囲に循環させた円筒
状キャンを真空容器より絶縁保持し前記円筒状キャンの
外周に沿って前記フィルムＢを３０＠／ｍｍで移動させ
ながら二元蒸発源を用い加熱電子ビームをそれぞれｃｏ
に対して了ａ　ＫＷ　。(Example 2) A 7 μm thick aromatic polyamide film (hereinafter referred to as film B) was held insulated from a vacuum container by a cylindrical can around which a medium at 200°C was circulated, and a film was placed along the outer periphery of the cylindrical can. While moving the film B at a rate of 30@/mm, heating electron beams were applied to each co-heater using a binary evaporation source.
For KW.

Ｃｒに対して４０　ＫＷ投入するように制御してＣｒが
２０重量％となる強磁性金属薄膜である垂直磁化膜を０
．２μｍの厚さで形成した基板を得た。A perpendicular magnetization film, which is a ferromagnetic metal thin film with a Cr content of 20% by weight, was heated to zero by controlling the input power of 40 KW to Cr.
．． A substrate formed with a thickness of 2 μm was obtained.

蒸着に先立ち真空容器内部を２　Ｘ　１０　’ＴＯＲＲ
まで排気した後、酸素を導入して２　Ｘ　１Ｏ−６ＴＯ
ＲＲで前記強磁性金属薄膜を形成したがその時に円筒状
キャンには１３．５６　計の高周波電圧を印加した。Prior to vapor deposition, the inside of the vacuum chamber was heated to 2 x 10' TORR.
After evacuating to
When the ferromagnetic metal thin film was formed using RR, a high frequency voltage of 13.56 μm was applied to the cylindrical can.

この高周波電圧は陽極電圧３．５　ＫＶで入射波５１５
０　ＣＷ〕反射波５０　［Ｗ’：］の整合状態を保持し
た。This high frequency voltage has an anode voltage of 3.5 KV and an incident wave of 515 KV.
0 CW] Reflected wave 50 [W':] The matching state was maintained.

前記基板を大気中に取出し、１日後に潤滑剤溶液を乾燥
後の膜厚が約５０八になるように前述の塗布機を用いて
基板に塗布した。The substrate was taken out into the atmosphere, and one day later, a lubricant solution was applied to the substrate using the above-mentioned coating machine so that the film thickness after drying was about 50%.

塗布に用いた潤滑剤溶液は潤滑剤であるステアリン酸を
メチルエチルケトンに溶解させたものである。塗布速度
は、７６　ｍ／ｍＭで、比較例と共に各々５０００７７
Ｈの基板を夫々５等分して１０００ｍ単位で塗布をくり
返し、８１１１Ａ幅の磁気テ１プにしてＶ、Ｔ、Ｒでの
くり返し走行を行った。The lubricant solution used for coating was prepared by dissolving stearic acid, a lubricant, in methyl ethyl ketone. The coating speed was 76 m/mM, and 500077
Each of the H substrates was divided into 5 equal parts and the coating was repeated in units of 1000 m, and a magnetic tape with a width of 8111A was used to run repeatedly in V, T, and R directions.

３０　’Ｃ、９０％　Ｒ，Ｈ，ノ環境で夫々１７）テー
プを１００回くり返し使用してジッターが画面にはっき
り現れたテープ巻数は本発明品では皆無であったが、比
較例では６０巻中５０％であった。30'C, 90% R, H, respectively 17) When the tape was used repeatedly 100 times, there were no tape rolls in which jitter clearly appeared on the screen with the inventive product, but out of 60 tape rolls with the comparative example. It was 50%.

別の角度から耐久性を調べるためにＶ、Ｔ、Ｒをスチル
フレームモードで操作し、３０’Ｃ，９０％、ＲＨで各
テープの任意位置を１ｏ個所選んで再生出力が３ｄＢ下
がるまでの時間は全テープで測定点５００に対して、本
発明品は全て３０分以上であったのに対し比較例では５
分以下が３４点、５分から１０分が２１点、１０分から
３０分が１３１点とバラツキがあり、かつ耐久性も明ら
かに劣っていた。To examine durability from a different angle, operate V, T, and R in still frame mode, select 10 arbitrary positions on each tape at 30'C, 90%, RH, and time until the playback output drops by 3 dB. With respect to 500 measurement points for all tapes, all of the products of the present invention took more than 30 minutes, while the comparative example took 50 minutes.
There were 34 points for less than 1 minute, 21 points for 5 to 10 minutes, and 131 points for 10 to 30 minutes, and the durability was clearly inferior.

発明の効果 以上述へたように本発明の方法によれは既存の塗布機の
一部に例えば電位規制ローラーを配するだけで、従来面
」人件に難のあった金属薄膜型磁気記録媒体の順次性と
りわけ、Ｖ、Ｔ、Ｒでのくり返し使用による走行不安定
現象によるシック−発生に起因した画質の低下のない、
メチルライフの長い磁気テープを再現性良く大量に得る
ことができる０Effects of the Invention As described above, the method of the present invention can be used simply by arranging, for example, a potential regulating roller in a part of an existing coating machine, and can be used to produce metal thin film magnetic recording media, which has traditionally been labor-intensive. Sequentiality: In particular, there is no deterioration in image quality caused by sick problems caused by running instability caused by repeated use of V, T, and R.
Magnetic tape with long methyl life can be obtained in large quantities with good reproducibility0

【図面の簡単な説明】 第１図は磁気記録媒体の断面図、第２図は本発明の実施
に用いた塗布機の一例の要部構成図、第３図は比較例の
基板の塗布時の表面電位の長手変化の一例を示す表面電
位特性図である。 １−　支持体、２−−−一強磁性金属薄膜、３・・・・
・潤滑剤塗布層、４　基板、５　アプリケ−タロ−ノペ
６　潤滑剤溶液、１１　・電位規制ロール。[Brief Description of the Drawings] Figure 1 is a cross-sectional view of a magnetic recording medium, Figure 2 is a diagram showing the main parts of an example of a coating machine used in the implementation of the present invention, and Figure 3 is a comparative example during coating of a substrate. FIG. 3 is a surface potential characteristic diagram showing an example of a longitudinal change in surface potential of FIG. 1-Support, 2--1 ferromagnetic metal thin film, 3...
・Lubricant coating layer, 4 Substrate, 5 Applicator nope 6 Lubricant solution, 11 ・Potential regulation roll.

Claims (1)

【特許請求の範囲】[Claims] 支持体上に形成した強磁性金属薄膜上に潤滑剤溶液を塗
布する際に、前記強磁性金属薄膜を一定電位に保持する
ことを特徴とする磁気記録媒体の製造方法。A method for manufacturing a magnetic recording medium, which comprises maintaining the ferromagnetic metal thin film at a constant potential when applying a lubricant solution onto the ferromagnetic metal thin film formed on a support.